#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <sched.h>

int ticket = 0;
pthread_mutex_t mutex;
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

void *route(void *arg)
{
    char *id = (char*)arg;
    while (1) {
        pthread_mutex_lock(&mutex);
        if (ticket > 0) {
            usleep(1000);
            printf("%s sells ticket:%d\n", id, ticket);
            ticket--;
            pthread_mutex_unlock(&mutex);
        } else {
            printf("%s wait on cond!\n",id);
            pthread_cond_wait(&cond,&mutex);//醒来的时候,会重新申请锁!!
            printf("%s 被叫醒了\n",id);
        }
        pthread_mutex_unlock(&mutex);
    }
    return nullptr;
}

int main(void)
{
    pthread_t t1, t2, t3, t4;

    pthread_mutex_init(&mutex, NULL);

    pthread_create(&t1, NULL, route, (void*)"thread_1");
    pthread_create(&t2, NULL, route, (void*)"thread_2");
    pthread_create(&t3, NULL, route, (void*)"thread_3");
    pthread_create(&t4, NULL, route, (void*)"thread_4");
    int cnt = 10;
    while(true)
    {
        sleep(5);
        ticket += cnt;
        printf("主线程放票咯! ticket: %d\n",ticket);
        pthread_cond_signal(&cond);
    }

    pthread_join(t1, NULL);
    pthread_join(t2, NULL);
    pthread_join(t3, NULL);
    pthread_join(t4, NULL);
    pthread_mutex_destroy(&mutex);

    return 0;
}